The present invention relates to a method for cutting a junction board provided with chip areas including integrated circuits every chip area, and a chip obtained by using the cutting method.
There have been proposed various ones as a method for cutting a substrate or board provided with chip areas including integrated circuits for every individual chip area. Related arts will be explained below by citing three examples.
(First Related Art)
A substrate having chip areas provided on one main surface thereof is prepared, and the chip areas are protected by a protective film or the like. In this condition, grooves are defined in cutting predeterminate areas by wet etching. Then, the substrate is cut in widths narrower than the widths of the grooves from one main surface side using a grindstone (dicing blade) to thereby separate individual chips from one another (refer to, for example, a patent document 1 (Japanese Unexamined Patent Publication No. Hei 6(1994)-268060 (Page 2 and FIG. 1)).
(Second Related Art)
A substrate having chip areas provided on one main surface thereof is prepared. Wet etching is performed in the direction orthogonal to an OF (Orientation•Flat) from the other main surface side of the substrate to form separation grooves extending to one main surface. Then, the substrate is cut in the direction parallel to the OF from one main surface side using a grindstone to separate individual chips (refer to, for example, a patent document 2 (Japanese Unexamined Patent Publication No. Hei 5(1993)-285935 (Pages 3 and 4 and FIG. 1)).
(Third Related Art)
A substrate having chip areas provided on one main surface thereof is prepared. Halfcut dicing is performed in the direction parallel to an OF as viewed from one main surface side of the substrate to form cutting grooves. Then, the whole surface of the substrate is thinned up to the cutting grooves from the other main surface of the substrate. Finally, wet etching is performed in the direction orthogonal to the OF as viewed from the other main surface side to separate individual chips (refer to, for example, a patent document 3 (Japanese Unexamined Patent Publication No. Hei 5(1993)-285937 (Pages 3 and 4 and FIG. 2).
Meanwhile, any of the first through related arts relates to a method for cutting a substrate formed of a single material. No consideration has been made as to the cutting of a junction board in which two types of substrates different in hardness from each other are bonded to each other.
A method called step cut has heretofore been used in the cutting of the junction board. The step cut is a method for exchanging dicing blades for each of two types of substrates constituting a junction board and cutting the junction board. That is, a problem arises in that the cutting of the junction board must be carried out in two stages upon the step cut and hence it takes a long time to cut it by the dicing blade.